Prior quick disconnect designs can often incur high pressure drop and associated energy losses at rated fluid flow conditions creating flow resistance in the system. For what may be the dominant technology, the poppet style quick disconnect, this flow resistance may be attributed to the tortuous and restricted flow path around the outside of the retracting poppets. The problem may become particularly troublesome when cryogens are pumped over long distances or through a complex configuration of valves and disconnects. Some efforts to address the problems of flow resistance may require larger pumps and more energy consumption to compensate for flow losses, creating additional problems relative to such past attempts in disconnect technology.
Furthermore, prior quick disconnect designs can typically waste a significant amount of fluid to the environment each time mating and de-mating occurs, creating fluid spillage and other potentially negative results. The spillage volume can be a function of the interface geometry of the mating halves of the disconnect. Aside from wasting valuable fluid, the problem can also pose safety risks if the fluid is toxic or an explosive substance such as liquid hydrogen.
Prior quick disconnect designs may also typically require high component weight to achieve required flow rates, representing a high mass-to-flow ratio. This can be a function of the length, envelope and complexity of the disconnect. Of particular concern for flight fueling systems, is the weight of the flight side half of the quick disconnect, which is attached to the launch or other vehicle and must be lifted into space or elsewhere. These prior designs may further require unacceptable engagement forces necessary to ensure proper operation, leading to an unnecessarily burdensome engagement sequence.